Down the hole (downhole) drills have found wide acceptance in drilling rock in hole sizes to twenty four (24) inches. In larger sizes economics of producing the limited numbers involved have further limited down hole drill acceptance.
It is therefore an object of this invention to produce an effective down hole drill of larger diameter and lower cost.
An object of the invention is to effectively combine or gang a plurality of smaller economically manufactured drills in a versatile package suitable for drill string attachment as a down the hole drill.
These and other objects are obtained in a gang drill for rock boring and the like comprising:
An assembly of a plurality of rock drills in a drill casing. The casing being further provided with alignment means and securing means for each of the drills of the plurality of drills.